Error Identification

[ocean_soul]

There may be a mistake in A,B or C or no mistake at all:

1.I am writing A.to express my deep concer B.on the fact that my order C.has not been delivered.
2.These days,A.although he still B.gives C.advices to his colleagues, he has retired from research.
3.Thor Heyerdahl is A.famous for his Kon-Tiki rafl expedition across B.the Pacific , and other voyages in which he sought C.to trace ancient maritime links between continents.
4.What a surprise it was A.to have received a letter from you B.after C.all this time!
5.Many road accidents A.occur because B.motorists cannot assess the speed of C.approaching vehicles.
6.A.The better education is indeed crucial B.to creating a society based on C.opportunity.
7.The editing exercises and the final examination are good ways A.for teachers B.to evaluate C.students' work.
8.Typically, A.parents have no idea their children are B.in distress C.much more less on the verge of a nervous breakdown.
9.A.Like B.head of state, the President C.determines the basic guidelines of domestic and foreign policy.
10.It A.should have rained last night B.as there's a puddle C.on the balcony.
11.They have severe problems at the moment and A.things B.are not looking C.well.
12.Where are A.the rest of the class? They B.should have been here C.ages ago.
13.He telephoned A.to tell me that he B.couldn't attend the opening of the exhibition tomorrow because he C.would fly to London.
14.As far as I can remember, the case A.against the bank robbers B.was being dismissed C.for lack of evidence.
15.A.The statistics that B.are available rely on C.worker's compensation data and hospital records that are incomplete.

My answers:1-B.of
2-A.even though
3-No error
4-A.to receive
5-C.the approaching vehicles
6-A.better education
7.No error
8.-C.much more
9-A.As
10-A.must have rained
11-B.do not look
12.No error
13.No error
14-B.was dismissed
15-A.statistics

[Barb_D]

There may be a mistake in A,B or C or no mistake at all:

1.I am writing A.to express my deep concern B. over the fact that my order C.has not been delivered.
2.These days,A.although he still B.gives C.advice to his colleagues, he has retired from research.
3.Thor Heyerdahl is A.famous for his Kon-Tiki rafl expedition across B.the Pacific , and other voyages in which he sought C.to trace ancient maritime links between continents. No error
4.What a surprise it was A.to have received a letter from you B.after C.all this time! I don't see "to have received" as an error if you are talking about something in the past instead of something that just happened a few moments ago.
5.Many road accidents A.occur because B.motorists cannot assess the speed of C.approaching vehicles. I don't see an error here either. "Approaching vehicles" is a general noun.
6.A.A or zero article better education is indeed crucial B.to creating a society based on C.opportunity.
7.The editing exercises and the final examination are good ways A.for teachers B.to evaluate C.students' work. Looks okay to me
8.Typically, A.parents have no idea their children are B.in distress C.much lesson the verge of a nervous breakdown.
9.A.As B.head of state, the President C.determines the basic guidelines of domestic and foreign policy.
10.It A.must have rained last night B.as there's a puddle C.on the balcony.
11.They have severe problems at the moment and A.things B.are not looking C.good. (OR: Things are not going well - this could be either - bad question!)
12.Where are A.the rest of the class? They B.should have been here C.ages ago. In American English "Where are the rest of the class" would be "Where is..." but "are" was not an option here.
13.He telephoned A.to tell me that he B.couldn't attend the opening of the exhibition tomorrow because he C.is flying to London.
14.As far as I can remember, the case A.against the bank robbers B.was being dismissed C.for lack of evidence. This could be okay if it describes what's going to happen soon - probably they want you to say it "was dismissed" and "due to" lack of evidence.
15.A.The statistics that B.are available rely on C.workers' compensation data and hospital records that are incomplete.

My answers:1-B.of
2-A.even though
3-No error
4-A.to receive
5-C.the approaching vehicles
6-A.better education
7.No error
8.-C.much more
9-A.As
10-A.must have rained
11-B.do not look
12.No error
13.No error
14-B.was dismissed
15-A.statistics

{not a teacher}

[David L.]

3.Thor Heyerdahl is A.famous for his Kon-Tiki rafl expedition across B.the Pacific , and other voyages in which he sought C.to retrace ancient maritime links between continents.